Carburetor



May s, 1928' l. T. swARTZ ET AL CARBURETOR 2 Sheetssheet l Filed May 5, 1925 www ,NVENToRS BY t b l r .NIU

May 8, 1928. 1,669,070

l. T. SWARTZ ET AL CARBURETOR Filed May 5. 1925 ma 2 Sheets-Sheet 2 Trl. l i

17x .3. ll' 5K 60 gf l/lf-"jq 323/ i f 7I i a l, i z@ @ig/zwi# 1 ATTORNEY.

Patented May s, 192s.

fufNi'rfEifD ST Ares PAT-.Buff oem-CE. l

:ma m. swan-,nmz .mn immun n; Mumien aNmANAnoms, mNDrANA; fsAID BAKER ,assioma mo sun stumm. Y i r CABBURETOR.

.Application `lcd 4May 5, 1925. Seria1.No.. 28,215.

Our invention .relates to a carburetor intended primarily for use in motor lvehicles and it is an object of the inventionfto Iprovide a .device of this character which shall cause fthe driven vehicle'to pick up 4speed` of fuel. In addition `'to the `rapid acceleration above referred tothe performance of the motor vehicle is improved "in 'that itis started easily, gets away quickly and 'has a remarkablepull at low speeds with Awide open 'throttle which affords exceptional -hill climbing ability. By reason oftheimproved fuel mixture in^the carburetor theexplosions `in 'the engine are `more uniform, the vibration Yis reduced and tl1e.'-'running of the/en-VJ gine is verysmooth. i y

'It is a 'well established fact that "internal combustion engines are -inuch more-difficult to voperate eiliciently .at low speeds, :and *the 'demand on carburetors at these speeds-of 10 miles and under is yone ofthe*finostfditlicult problems in carburetion. Y

This condition is due tothe fact/that lfuel mixtures at low speedsmustlbericher. The reduced air -flow Lat closed :throttle positions snakes `separate idling fdevices imperative, and :the synchronizing .of the vtwo separate fuel supplies thusiidemanded, `(main .and idling) diilicult `and extravagant. One of lthe Y.important objects :of .our .1invention ther.e- .fore sito sprovide improved vmeans in a cary.huretor for :regulating the [supply of fuel r .lat :low speeds.

it is .a well `known Vfact that icarburetors Ado 3not vdeliver to the engine arperfectv .mixture of air and gasoline, :as a gas, ralsolthat the Amixture `is fullof drops or yglobules off gasoline; -one reasonfbeing'fthat tlieauxiliary -air Iis not properly mixed with the'stream of Athe main or huretor and intake manifold o'f 'to avery great extent. 4 gases of even slightly different specific gravisimilar reference characters indicate atomized liquid `and air, at and beyond 4the point, where the current of auxiliary .joins primary stream of air, carrying misted gasoline in suspension.l Another reason is that stratification occurs in the carthe engine 'It is well known that ties are .very prone to. stratification `and .that iti-s a difficult matter to produce a 'fairly uniform mixture of two {gases of .somewhat -dilferent specific gravities.

lhe specific gravity ofgasoline vapor is much greaterthan that of-air, and the specific gravity oi air with liquid Vgasoline in suspension `is higher than that of gasoline vapor. Ordinarily the auxiliary air passes intothe lengine intake at the side of the pri'- mary current of air with m'isted gasoline in rmechanical suspension and without proper mixture with such primary current. The lcondition vexisting` in the ordinary carbu` retorfis therefor particularly such as favors stratification, as against thorough,.iiiixture,

and *this tendency to `stratiiica'tion is further -eiil'ianced 'by the ordinary butterfiy `or throt-V tle valve, which'is commonly so placedl als to favor Ypassage of the auxiliary air along one rside of the butterfly valve, v4the passage of `the principal portion 'o'f the and to vfavor aprimaryair `current wlth ygasoline in Suspension, alongjthe lother side of the valve. It seems that this stratification tends (to persist all the 4way 'to the engine cylinders and is 'ithe cause, or at least an important cause, of 'imperfect combustion and uneven 'firing in the @vlinders off-a multi-cylinder engine.

`Referring to 'the accompanying drawings 4which'are made a part hereof and on which similar parts, f

Figure l `is a plan of our improved device,

Figure 2, a horizontal section su'hstan` tielly ron line n2 2 of Fig. 3, with Vthe dioat Ichaniher disposed Iat right anglesfor purjpose of illustration.

Figure 8, a vertical centraly .section of Fig. IFigure 4,'a "fragment of Fig. 2 showing certainfparts in adilferent position,

Figure 5,' asecltion on line 5^`5 ofFg. )3,

Figure 6, a section on line 6-6 of Fig. 4, and

Figure 7, a detail of an idling device shown in Figs. 2 and 3. Y

in the drawings reference character 10 indicates the outer casing of the carburetor which is provided with a fuel chamber 11 containing float 12. 'lhe float controls the position of a needle valve 13 by means of which the fuel inlet 14 is opened and closed in well-known manner. 'lhe float has a stem comprising a hollow section 15 containing a spring 16 engaging at. its upper end another section 17 having a pin and slot connection at 18 with the lower section to limit their relative movement. Levers 19 have weights at t-heir outer ends and engage at their inner ends in a groove at the upper end of section 17, these levers being pivoted at 2O upon downward extensions from a plate 21 forming the upper wall of this part of the fuel chamber. This arrangement provides means for maintaining a i'ixed fuel around the nozzle from the exhaust manilevel in the chamber, the spring 16 allowing a slight resiliency between the valve and the float and serving to prevent the valve from raising and lowering on.its seat and so admitting the fuel to the chamber unnecessarily so as .to raise the level above the normal. rlhe reduction of pressure in the float chamber due to suction from the engine causes the float to raise slightly and force the valve 13 more tightly on its seat until this reduction of pressure is overcome by the ingress of more air whereupon the float rebounds or slightly lowers to its normal position without admitting excess fuel into the float chamber. Because our nozzle is placed relatively high above the fuel level and also because of the lifting action of the air on the fuel in the passages, it not necessary to .maintain an absolutely accurate fuel level, wherefore we are able to do away with all float valve adjustment.

In the present embodiment of our invention the mixing chamber is somewhat elongated as shown in the drawings and is open at one end, as indicated at 22, for admission of air which preferably heated by the exhaust of the engine or in some other manner. A choke valve 23, here shown as being of the butterfly type, is provided at this end of the chamber for reducing the supply of air as in starting the engine. The upper end of submerged air vent tube et?) is open to atmospheric pressure, said tube extending beyond choke valve Q3 and when the choke is closed the suction of the engine is relieved through this tube thereby taking a richer mixture of fuel into the engine.

A rockarm 24 on the pivot of the valve is operated from the dashboard of the car in the usual manner. A nozzle 25 is shown as located concentrically of the mixing chamber which is narrowed adjacent the opening of the nozzle to provide a venturi indicated at 26. ln the present embodiment of the invention the nozzle is shown as having a removable end piece 27 (Fig. 2) screwed into the body of the nozzle, said end piece being flared or bell-shaped at its other end and terminating in a thin practically knife-edged rim adjacent the smallest part of the venn turi. rlhe outside shape of the nozzle, and the relative position of the nozzle in relation to the Venutri neck, permit a suction to be createdpdirectly in front of the bell of the nozzle, which suction is transmitted to the passages behind the nozzle and is the reason why air passes down through the submerged air vent tube 43, (i. e. to relieve this suction). The rear part of the nozzle just beyond the right angle bend is enlarged to reduce momentarily the velocity of the fuel and give a larger surface for the liquid fuel in the mixture to adhere to, thus exposing a larger surface to the incoming heated air fold. lt acts as an expansion chamber for the fuel that is heated in its passage from the preliminary mixing chamber.

A throttle-actuating rockshaft 2S is mounted to move about a vertical axis on the forward extension of the mixing chamber, said rockshaft having secured thereto at its upper end an arm 29, for connection to control levers of an automobile in usual manner. Another arm abuts against an adjustable screw 3() to limit the movementof the rockshaft and the throttle and a third arm is connected to a link 3l by a screw 32 for a purpose hereinafter described. At its lower end the rockshaft has secured thereto a pinion meshing with a rack 311 secured at its forward end to a throttle disk 35 fixed to the forward end of a rod 36 sliding in a bearing on a block 37 in the mixing chamber .for movement axially of said chamber, this disk taking the place of the butterfly throttle in general use.

The disk is held in place on the rod by a threaded extension 38 (Fig. 7) engaging a threaded opening in the end of the rod and said extension is secured to or preferably formed integral with an idling collar 40. An auxiliary nozzle 39 isfastened to the extension 38 and idling collar 10. The auxiliary nozzle 89 has a longitudinal openino aligning with the passage in the nozzle 2o but of a smaller diameter, said auxiliary nozzle being flared at its forward end and at its rear end being shaped to fit .inside the part 27 in a manner to provide a tapering extension of the narrowest part of the passage through the removable end piece 27. rlhe auxiliary nozzle also carries the concentric annulus or -idling collar 40 as above stated comprising a cylindrical portion with a radially extending flange and; ar rearward flared opening 4l.. ,f The` taper et Said flared opening is such as Vto enable it to fit Closely about the rim of the removable end piece 27 of the main nozzle and its radialflange constricts to a cons iderableextent the space between said rim and the inner Wallofthe venturi, thus increasing the velocity of the air stream.

The location of the disk 3.5 and the aux iliary nozzle with its associated, parts is such that when the throttle is brought into idling position relative to the venturi, as indicated in Figure 3, the flared part ofthe idling eollar engages the rim at. the end of the mai-n nozzle as above described. The annular space between the throttleand. the venturi .is now very small yWhile at the `,same time the space between the venturi and the main nozzle .has been greatly decreased and the operative narrowest part ofthe fuel channel has been reduced and brought relatively near the throttle whereby the amount of air passing through the mixing chamber is greatly decreased. current is however, increased due to the narrower passages about the idling collar and the throttle.

As the valve and thecarbureting cham-Vv ber, in which the valve functions, are circular, and as the valve always maintains the same axial ahneinent, the space between the Walls of the carbureting chamber' and the throttle valve Will be kuniform at any part aroundv the valve, so that a clear passage way at all throttle openings is provided which. prevents stratification in the iuel stream. The walls in the carburet-ing chan'iber are tapered and the degree of the taper determines the volume of the fuel mixture at any throttle opening, hence the` control oi" the speeds at any predetermined opening oil, the throttle. The globules of fuel shoot out ot the spray nozzle bombarding the dish and are broken up, while the air takes the shortest pathv and picks up the broken globules at the disl; edge, lthus the throttle disk tends to; further break up the gasoline globules o n their Way to the kintake manifold and to further min the fuel stream. g

Because our fuel mixtures. at idling or higher speeds all come through the ina-in spraying nozzle there is no hesitation or rich or lean spot When the idlingetlow begins and' tne main tuellou' ceases or vice Versa. This hesitation .is noticeable in most carburetors.

This is Why our "carburetor responds inf stantly to the dillerent fuel demandswith` out hesitationand cannot be loaded. The neck of the nozzle at 4-2is relatively thin and is exposed tothe heat of the air enter ing at 22. This helps to expand the air and vaporize the fuel; passing said neck.

The velocity of the air Just behind the nozzle there is abrenehpasf Sage, 4 3 ,leading trein the annosphere.l

Air is. ledthrough this paesagedown below the liquid level. kWhere it lenters thefuel chamber through encor more of a pluraly ity ot ports 4e otk varying size, the smallest nearest the'suntvface of the liquidi-fuel andthe ports .increasing size toward the bottom et the chamber.k Iny the operation oil the engine the air willr be dra \,\*n,th,rough the tube43 with a force increasing withY the increasing speed of the engine so-as to enter through an increasing number ot' ports thus providing earbureted er hydrearbon-saturated airfor use as hereinafter described in aeeordanee with the demands oit' the.. engine. At. very slow speeds or when idling the suction of the engine may-be insni'icient to draw the. needed air through any oif ythe ports libe-low the fuel level, aint at such times, they throttle being near-ly closed, air

ngiust enter the fue-lchan'ilnersubstantially,

at atmospheric pressure tor whicl-r purpose I haveprovided a port at 45, above, the nor mal. fuel. level. This port also serres torelieve the air pressure when iilling the float chamber. Since the air entering the passage 43 is heated it will also warm the, lower part ofthe nozzle and; adjoining parts to someextent; which also aids in the operationof the Carburetor by heating to some extent thefuel stream passing to the spraying nozzle.-

Underneath the nozzle there is a cham! ber-ehereinatter referred toas a preli1ninary mixing chamber, said chamber conim-unicatng directly with the passage 46 through` the nozzle. The. main fuel passage i? enters the preliminary mixing chamber from beneath saidv passage being here shown ase-Xtendfi-ng vertically upward from a horizontal branch opening out ot the fuel chamber. A vertical passage 48 connects atk its longer end with a horizontal passage 4,7 which is provided with a port (S5 for the admission oli liquid fuel which is carried with the carbureted air along: passage 47 to the passage leading to. the preliminary mixing chamber. This. passage is the main passage for carbureted air Vtrom the upperpart of the fue-l chamber, which air has been carbureted by its passage through the fuel by WayA of ports 4A..

An auxiliary fuel passage at 49 leads into the preliminary mixing chamber troni a pointk above the. normal fuel level, this passage being here shown as formed partly in a casting in whichis formed the passage 48 and part of the passage 41. At its outer end the` passage 49 opens into orifice 50v in a tube l5l having Ya port 52 near the top of the fuel, cha-nnber.Y The suction in tube 5l?` causes the tuelto rise and meet the air through orifieeefl,l and ini-XV with uit. The

opening or closing of orifice 52 controls the `amount of fuel lifted through orifice 50.

The main fuel passage is provided with a plunger valve 62 adapted to close with the throttle lfor slow motor speed (see Fig. 3), and the suction of the motor in the carburetor is so increased as to cause a spray of fuel to be injected into the port by the air entering through the orifice 52 to provide a. mixture for ope ating the motor at slow speed. The air port 52 is varied in size by means of an auxiliary air valve in the form of a sleeve 54 supported above the fuel chamber and provided with a cut-away part having a diagonal face at 55 which when the tube 51 is rotated gradually closes the orifice 52. It will be noted that there is constant communication between the chamber in the tube 51 and the port 50 and a similar opening is provided for forming communication between the tube 51 and the `substantially vertically disposed elongated passage 53 which has its open lower end terminating below the normal level of the fuel in the fuel chamber. The tube 51 is rotated by means of a roclrarm 56 secured to the upper end thereof pivotally attached to the link 31 by a screw 57. An annular fiange 5S at the upper end of the sleeve serves for adjustment of the sleeve by means of a screw 59 passing through a slot in the flange into a fixed part of the carburetor. At its lower end the tube 51 carries an ec centric pin 60 enga-ging a yoke 61 (F ig. on said plunger valve 62 by means of which the main fuel passage 47 is opened or closed, so as to cut olf the main supply of fuel when idling. lNhen the plunger valve cuts off the main fuel passage this passage fills with liquid fuel and so acts as au accelerating well offering a supply of fuel immediately a vailable for rapid acceleration. r)The unusual size of all the passages is necessary on account of the emulsitied condition of the fuel. A. baille G3 enters the preliminary mixing chamber opposite the passage 49 and encounters the fuel stream entering from the tube 51 and serves to break up the globules or droplets of fuel and assist inmalring the charge uniform.

A valve for the main liquid fuel passage or main fuel stream 47 is provided by means of a screw G4 having a flat end for entering the port (i5. rt i s upper end a head (l is provided for turning the screw which is mounted by means of a tine thread in another screw (i7, the .screw 64 being adjusted to provide carbureting adjustment under runningr conditions, i. e., when the engine is hot. The second screw has a relatively coarse thread for temporary adjustment from the dash as for priming the engine for easy starting and for running until the engine gets hot7 and a limit is provided by a screw orother means whereby the screw 67 always returns to the same position when moved back and forth by the connection 68 from the dash7 which limit may of course be adjustable.

ln the operation of our device a main stream of air, which is preferably heated, will enter at 22 and pass to the mixing chamber and a. minor stream will pass into the tube 43. VThe minor stream may pass from the tube into the fuel chamber through the opening 45 and as the speed of the engine increases it will pass also through one or more of the ports 44 for which purpose it forces the fuel out of the way in the tube and rises through the fuel in the chamber. lt will be remembered that the fuel level in the chamber is maintained accurately by reason of the spring pressed valve 13 which permits entrance of fuel to the chamber only when positively lifted by the movement of the levers19fraising the lower section 15 positively through the connection of the pins with the upper section 17.

Air passing into the fuel chamber is carbureted or saturated to a greater or less degree with the more volatile constituents of the liquid fuel. in thel chamber. This air is admitted directly into the sleeve 54 which forms au inlet for air into the main fuel passage 47 when the valve (S2 is'opened. The Aiiow through the passage 47 is metered by the flat end of the screw 64 and the main fuel stream consisting at the lower speeds et liquid fuel mixed with bubbles of carluireted air and at the higher speeds an emulsified fuel due to the increased air veiocity7 flows into the preliminary mixing chamber where it strikes against the undersile of the baille 63 und is thus further bleken up.

An auxiliary fuel stream enters the preliminary mixing chamber at right angles to. the main fuel stream and is directed against the flat end of the screw G3 which forms a batlle for the auxiliary fuel stream also. The auxiliary fuel stream consists of carbureted air controlled by the auxiliary air Valve and the current of air passes over the fuel in the passage where it takes up a certain amount of additional fuel due to the suction created at this point. The auxiliary current consisting principally of air in a saturated state mixes with the spray in the preliminary mixing chamber and the mingled product passes up into the nozzlerf where it is exposed first to the heat passing through Iihe thin neck lf2 and then to the heat in the walls of the enlarged chamber in the nozzle. At this point any uuvaporized fuel will be thrown against the upper and rear walls of the chamber in the nozzle due to the bend in thecurrent and will be sprayed out in a thin film so as to be fully exposed to the heat at this point. From this chamber the mixture passes through thc-flared` nozzle to be further mingled with the air passing through the venturi in well-known manner.

When the throttle approaches closed position, as shown in Fig. 3, arelatively small amount of air will passthrough ports 44 and,

in fact when at atmospheric pressure air will pass only through port 45. As the valve 62 closes, thc fiow through the main fuel passage is cut off and the fuel in said passage serves as an accelerating well when the throttle is again opened. As the throttle is closed the auxiliary air supply through port 52 to the preliminary mixing chamber is also diminished but the suction is increased whereby a spraying action takes place at the junction of the passage 53 with the air passage. The fuel after leaving the preliminary mixing chamber passesy up, as above described, but the auxiliary nozzle is now in the position indicated in Figure 3, as are also the idling collar and the throttle so that the fuel follows the path indicatedl by the arrows and is again very thoroughly volatilized.

It will be obvious to those skilled in the art that various changes may be made in our device without departing from the spirit of the invention and therefore we do not limit ourselves to what -is shown in the drawings and described in the specification but only as indicated in the appended claims.

`Having thus fully described our said invention, what we claim as new and desire to secure by Letters Patent, is: i

l. A carburetor having a mixing chamber,

. a fuel chamber, a nozzle in the mixing chamber, means for admitting air to the fuel chamber below normal fuel level to cause air to pass into the fuel and to become carbureted. a main fuel passage leading to said nozzle, a passage for the carbureted air from the fuel chamber merging with the firstnamed passage, and means for spraying fuel into such carbureted air in the second passage, substantially as set forth.

2. A carburetor as in claim 1;, with valve means for closing the main passage without interfering with said spraying means, substantially as set forth.

3. A carburetor as in claim l, with valve means for closing the main passage and varying .theadmission of air to the second passage without interfering with said spraying means, substantially as set forth.

t. 'A carburetor having a mixing chamber, a fuel chamber, a nozzle in the mixing chamber, means for admitting air to the ,fuel chamber below normal fuel level to cause air to pass into the fuel and to become carburetcd, a preliminary mixing chamber communicating' with said nozzle, a passage for fuel from the bottom of the fuel chamber to said preliminary mixing chamber, and a pasber above normal sage for fair leading to said preliminary mixing chamber from a point in the fuel chamfuel level, substantially as set forth. f i

5. A carburetor comprising a mixing chamber, a fuel chamber, a nozzle in the mixing chamber, means for admitting air to the fuel chaiuber, a. main fuel passage leading to -said nozzle, a passage coi'nmunicating with the-upper `portion of the fuel chamber and said main fuel passage for spraying carburctcd fuel thcreinto, and ialve means for simultauieously closing the main passage and for varying the admission of ca-rbureted fuel to the second passage, substantially as set forth. Y

6. A carburetor having a fuel chamber, a mixing chamber, an air passage leading into the fuel chamber below the normal fuel level to cause air to pass into thel fuel and tobecome carbureted,'a nozzle in said mixing chamber, an outlet passage leading from the fuel chamber into the nozzle, a fuel supply passage communicating with the outlet passage from a point below the fuel level, a carbureted air passage above the normal fuel level forming communication with said outlet passage, and .interconnected means foi` controlling said fuel supply and said carbureted air passages, substantially asset forth.

7. A carburetor having a fuelv chamber, a mixing chamber, an air passageleading into the fuel chamber below the-normal fuel level to-cause air to pass into the fuel and to become carbureted, a nozzle in said mixing chamber, an outlet passage leading from the fuel chamber into the nozzle, a fuel supply passage communicating with the outlet passage from a point below the fuel level, a carbureted air passage above the normal fuel level forming communication with said outlet passage, interconnected means for con,- trolling said fuel supply and said carbureted air passages, and means projecting into Said outlet passage and forming a baffle for fuel discharged against the same, substantially as set forth.

8. A carburetor having a fuel chamber, a mixing chamber, a passage for the admission of heated air to the mixing chamber, an air passage leading into the fuel chamber, a

yplurality of vertically spaced ports opening out of said air passage below the normal fuel level to cause air to pass into the fuel and to become carbureted, a nozzle in said mixing chamber, an outlet passage from the fuel chamber to theVK nozzle, a fuel supply passage communicating with said outlet passage from a point below the fuel level, and a carbureted air passage above the normal fuel level forming conmiunication with said outlet passage, substantially as set forth.

9. A carburetor having a fuel chamber, a mixing chamber, a passage for the admission of heated air to the mixing chamber, an

air passage leading into the fuel chamber, a buietecl air passage above the norma-l uel plurality of vertically spaced ports opening level forming communication with said outout of said air passage below the normal fuel let passage, substantiallvv as set ioith.

level to. cause air to pass into the fuel and to In witness whereof, We have hereunto set become Caibuieted, a port in said air passage oui hands at Indianapolis, lndiana, this` :25th 15 above the noi'inal fuel level, a nozzle in said day ol April, A. D. nineteen hundred and mixing' chamber, an outlet passage from the t\\'e11ty-five.

'fuel chamber to the nozzle, a fuel supply pasf Y sage communicating with said outlet passage IRA 'I S. SlVARTZ. Y

l0 from a point below the fuel level, and a cai'- ARTHUR R. BAKER. 

